Extrusion device



June 30, 1953 L. c. MILLER 2,643,620

EXTRUSION DEVICE Filed Nov. 22. 1948 6 Sheets-SheefI 1 Eau/0,05 C? ///MLE/e INVENTOR.

BY da June 30, 1953 L, C, MlLLER 2,643,620

EXTRUSION DEVICE Filed Nov. 22, 1948 6 Sheets-Sheet 2 June 30, 19.53 l.. c. MILLER ExTRusIoN DEVICE 6 Sheets-Sheet 3 Filed NOV. 22, 1948 `Fume 30, 1953 L. C. MILLER EXTRUSION DEVICE Filed Nov. 22, 1948 6 Sheets-Sheet 4 -se "Il O I2 49 55 550. 1 I 550- G0 3 58 3.3"L 8 55 55 5B i 52 i 57 57 u 55 I 58 74 75 G4 5| 52 6g, 14 66 14s 2g June 30, 1953 EXTRUS ION DEVICE Filed Nov. 22. 1948 4 6 Sheets-Sheet 5 HIll-II E S s I I. mmm

l.. c. MILLER' 2643,62O

June 30,' 1953 L. c. MILLER ExTRusIoN DEVICE Filed Nov. 22,- 1948 6 vSheets-Sheet 6 50u/ops C A/f/ase JNVENToR.

Ow 54K ,armas/EVS' Patented June 30, 1953 UNITED STATES PATE NT oFLFlci-zv lllix'ritusion DEVICE .Leonidas .C..Miller, Los Angeles, Calif. .Application Npyember 22,1948, :serum No. 61,419

` (C1. Ei- 14.)

-21 Claims. l

AThis `invention relates to apparatus Jfor yextruding `materia-l and has been found particularly useful V'in connection Iwit-h devices ffor -extruding afoodproduct. v

IAn important vobject of this invention is Lto provide an extrusion device `for eX-truding material supplied from a plurality of reciprocating piston and cylinder assemblies in a Amanner so that the extrusion pressure remains substantially constant during the complete -operating cycle of the machine.

Another object vis to provide an extrusion de- Vice employing a plurality 'of reciprocating elements feeding a common 'discharge passage lin which means .are provided for maintainingthe pressure in `the discharge passage vsubstantially constant during the change-over :interval when a lirstreciprccating element-reaches the end 'of its 'operative stroke ,and a second Yreciprocating element vbegins its voperative stroke.

Another object is `.to provide va device of `this type *having a novel lform of hydraulic 'system functioning to provide both rapid traverse Vand slow traverse for the `reciprocating elements and for vactuating the elements ina manner to "maintain Asubstantially constant pressure in vthe discharge passage. l I A y Another object is `j-to provide a device of this type which maybe operated manually under the control of an operator, vand which is :provided with a novel control system whereby 'it repeats its operating cycle automatically, requiring only that the. material for extrusion be supplied to the device at `the proper intervals in'its operating cycle.

vA more particular object is to provi-de an extrusion device having an extrusion head -provided with a passageway terminating in an -orince, together with a member adjustably positicned within ,the passageway for varying the size of the orifice.

Another object is to provide an `extrusion device having a novel form of adjustment means for l,varyimg thesize of a ring ytype orice.

A further .object is to provide novel vforms of check kvalves interposed between the reciprocating elements and vthe extrusion passage.

Qther objects and advantages will appear hereinafter. v

Figure iis a perspective view .of a 'preferred embodiment of my invention, the guards and covers being removed to show details of const-ruction. Figure 2 is a-perspective view partly broken away showing the extrusion `head assembly removed for purposes of inspection and cleaning.

`Figure 3 is a sectional plan view partly broken feed cylinders and away vshowing details of construction of the two showing their common discharge'h'ead.

Figure 4 is a 'sectional elevation through vthe extrusion head. Y

Figure 5 is aside elevation ofthe extrusion head land cutter mechanism looking at the left side'of the 'device as viewed in Figure 4.

Figure .6 is a sectional Vdetail taken substantially on the lines 6 as shown in Figure 3.

Figure 7 is a sectional detail taken substantially on the Alines `'I--l as shown in Figure 3.

Figure Sis la sectional yplan view partly broken awayftaken substantially on the lines 8 3 as shown in v'Figure 4. Y

Figure 9 is a sectional elevation taken substantially'on'the 'lines 9 9 as shown in Figure `3 and showing details of con'struction'of one of the vent valves.

Figure l0 'is a sectional elevation taken sube stantially on the lines Ill- I0 as shown in Figllle 3.

Figure 1l is va diagrammatic view showing the hydraulic circuits for reciprocating the pistons.

Figures 12 and 1,3 are diagrammatic views showing .porting of the Afour-way control valves.

Figure '14 is a sectional view taken substantially on the'lines I4-Id as shown in Figure 4.

Figure 15 is a sectional Velevation taken substantially on Athe lines I5-I5 as shown in Figure 14.

Referring to the drawings, a frame or base I0 is provided with suitable supporting wheel assemblies II and supports an oil reservoir I2. An electric motor I3 resting on the upper plate of the oil reservoir I2 isdirect connected to drive a double pump assembly I 4. Pressure fluid delivered by the :pump assembly Id is used for actuating alternately a pair of power .cylinder assemblies I5 and I6. .Each of these power cylinder assemblies is carried on the frame and each maybe of .conventional design. Piston rods I? and i8 actuated' by these assemblies I5 and I6 move the feed pistons I9 and 2t respectively within the corresponding feed cylinders 2| and 22. The feed cylindersv 2i and 22 are substantially duplicates and each supports a lateral projection 23 providing an upwardly facing opening 2li. The material to be extruded is inserted into the feed cylinders through the openings 243.

`The material to be extruded, which in this case constitutes a 4food product, is moved forwardly in one of the feed cylinders 'by the forward motion of the piston in that cylinder, and the material passes through yone of the check valve assemblies 25 and 2S into the-central chamber 2l of the extrusion head assembly generally designated 28.

is interruptedat intervals by a series of radialns 33 carried on the cap 32. The extruded material passes outwardly through the annular port 3G and is chopped oil at intervals by means of the oscillating cutter 34. The short strips of mate-V' rial thus formed drop by gravity into a cooking vat (not shown). f

Considering the operative parts of this apparatus in more detail, the extrusion head 28 includes a casing 35 which encircles a central hollow shaft 3G. A closure 3l is secured to the casing 35 by any convenient means such as, for

example, by the cap screws 38, and carries a ball bearing assembly 3S. The upper end of the hollow shaft 35 is provided with external threads 45 adapted to receive the corresponding internal threads formed on the nut 4l lwhich rests on the bearing assembly 33. Means are provided for preventing relative rotation between the casing 35 and the hollow shaft 36, and as shown in the drawings this means includes a keyway 42 formed axially in the upper end of the outer surface of the hollow shaft 33 and adapted to receive the key 43 carried on the inner end of the fitting 44 mounted on the closure 3l'.` The nut 4i is provided with means whereby it may be turned in order to advance and retract the shaft 3B axially within the housing 28. As shown in the drawings this means includes an` apertured ring '45 secured to the upper end of the nut by means of the attachment ttings 46 and provided with a series of openings 4l for reception of a transverse bar 43. Concentric packing rings 37a prevent leakage between the closure 3'! and the casing 35 and between the closure 3l and the shaft 3G. A connection ring 4S is attached to the lower end of the casing 35 by means of attachment fittings 5t, and this connection ring is press tted with relation to the removable wear sleeve 5l which carries the rim 3i at its lower end. The ring 4,9, sleeve 5i and rim 3| are mounted coaxially of the central hollow shaft 36. The removable wear cap 32 is secured to the lower end of the shaft 3G by means of the connection fittings 52.

From this description it will be understood that rotation of the nut 4l byv means of the bar 45 in the openings 41 serves to adjust the spacing of the cap 32 and the-rm- 3| and thereby vary the width of the ring orice 3i). This in turn controls the thickness of the extruded strips of food material. This is an important feature of my invention since it provides very accurate control of the thickness of the extruded strips. Furthermore, this feature insures uniformity of thickness throughout the peripheral length of the ring orifice 33, by greatly facilitating the ease of removing accumulations of material from the orice-dening parts. Since the cooking time must be the same for each of the strips extruded, and since the thickness of the strips must be accurately regulated with relation to the time of cooking for optimum results, it is very important that there be no variation in thickness during any part of the cycle of operation of the machine. The constructional features just described which provide accurate control for the thickness of the extruded strips are also important for ease of disassembly for periodic cleaning. The projections 33a formed at the outer ends of each of the fins 33 may contact the lower end of the rim 3l to provide a stop to limit the upward travel of the stein 36. This stop means control the minimum thickness of the extruded strip of material.

The oscillating cutter 34 reciprocates vertically on the outer cylindricalsurface of the sleeve 54 and rim 3hA Thissurfacef may be'interrupted by axially extending grooves 53 `to reduce the surface area in contact with the reciprocating cutter 34.

f Guide rods 5d are mounted to slide vertically within bushings 55 carried on radially projecting lugs 56. These lugs 55 are carried on a. split ring 'l2 which encircles the ring 49. The ring-shaped cutter 3e which encircles the cylindrical rim 3i is provided with arms 5l which are secured at their outer ends to the guide rods 54 by means of the nuts 55.

Pairs of compression springs 59 and 50 encircle eachof the rods'54 and serve to provide. a noatingvmountingfor the rods and for the cutter 34. The upper springs 59 are considerably larger thanthe lower springs 63 with the result that the assembly, including the cutter 34 and rods 54, normally remains at rest with the parts in the position shown in Figure 4. The normal height of the cutter 34 may be adjusted without varying the Hspring settings by turning the threaded bushings 55 relative to the lugs 56, and then locking them in adjusted position by means of the ,lock nuts 55a. Means are provided for.

'l about which the rocker arms 6l operate.'

Rotation of the cam shaft 66 causes the rocker arm 6I to oscillate, as will be readily understood. Upward movement of the rods 54 carries the cutter 34 with them, and upon return travel in a downward direction the inertia of the rods 54 and cutter 34 carry them beyond their normal position of rest, with the result that the cutter 34 chops o material extruded through the circular orice 30, andquickly returns.

Adjusting nuts 'H are provided on the rods 54 for adjusting the compression of the springs 59 so that the amount of. over-travel of the cutter 34 may be regulated as desired independently of the effective stroke of the cams 6l. The cam shaft 6B may-be formed in two partsand connected by means of an angularly adjustable coupling 13. An enlarged ange on the end of the shaft section 56a is provided with arcuate slots 66o through which cap screws 66d extend axially. These cap screws are threaded into the enlarged companion flange on the end of the shaft section G51). A ring 66e encloses the heads of the cap screws. This coupling assembly 13 may be angularly adjusted initially to cause thecams 6l to operate in synchronism, and also provides angular adjustment to compensate for uneven wear.

A disconnecting coupling 14 is provided at one end of the cam shaft 6B for connecting the cam shaft B6 in driving relation with the power Shaft l5. As shown in Figure 1, this power shaft 'I5 n is carried in a bearing '1B positioned on the frame a vertical post 8 0 4extends upwardly lfrom theV base of the frame and projects above the llevel of the extrusion head 28, Horizontal Varm 8| extends from the post and supports a toothed wheel 812 Carried between tension straps 83. This i wheel is connected to a hand knob 84 so that `it may be rolled along the horizontal rack 85 when desired. The tension straps support a bail 86 which is connected to the extrusion .head at a location near the center of balance. The head 28 is provided with a vertical plate S1 having ports 88 and 89 which are adapted to be aligned `with registering ports 90 and 9| respectively provided in the vertical plate 92 mounted on the frame The plates 81 and 92 are provided with matching ground surfaces to prevent leakage when the plates meet in metal-to-metal contact. Suitable packing rings (not shown) encircling the ports may be utilized if desired to supplement the seal provided by the ground surfaces. Channel strips 93 and 94 are positioned above and below the matching plates 91 and 92 and when clamped together by means of vertical bolts 95 serve to hold the vertical plates 8.1 and 92 in sealing relationship. These bolts are conveniently actuated by means of cam levers 9S connected to the upper ends of the bolts. When it is desired to remove the extrusion head 28 from the base |0 the cam levers 99 are moved from the locked position shown in Figure l to the unlocked position shown in Figure 2, thereby permitting separation of the channel retainers 93 and 94 under action of the expansion springs 91. The bolts 95 are each lsliclably mounted in central guides fixed to the stationary plate 92, and the lower ends of the bolts are secured to the lower channel retainer 94. One end of each spring 91 engages a boltencircling bus-hing and the other end engages one of the central bolt guides. When the camlevers 9S are turned .to their unlocked position, the upper springs 91 raise the upper channel retainer 93 vand the lower springs 91 depress the lower channel retainer 94. The extrusionhead 20 may be then moved away from the frame and is conveniently supported by means of the tension straps 93 and bail ,8B from the horizontal arm 8|.

Counterbores 9B areprovided in the vertical plate 81 encircling the ports 9 8 and 89. These counterbores are adapted to receive the flange 99 lof a conical valve seat member |90. This valve seat member `iS mounted within the head 2.8 `and such :that .the spring |08 acts to move the dise to the feed cylindersandvare so constructed that the -woriingnparts -of the valve assembly are elle closed and maintained out kof contact with the.

food product material which is to be extruded.

A vertical plate |20 mounted 4on the `frame 0 separates r the feed cylinder assemblies 2| V.and 22 from 'the power cylinder assemblies 5 and I6. Suitable screw vcnnnections |2| extend through this vertical plate to lsecure the cylinder assemblies l5 and l0 in operative position. Similarly, screw ttings |31 extend through this plate tto hold the feed cylinders 2| and 22 in operative position. Suitable hydraulic leads are provided to each end of the dou-ble acting cylinder assemblies I5 and I5 so that the piston rods |1 and I5 ymay be reciprocated as desired.

',Each of the feed pistons I9 and 20 is provided is provided with a frusto--conical sealing surface |0|. A check valve |02 is provided with a sealing surface |09 adapted to rest against the 'surface |0|." As shown in Figure '1 this check valve |02- may include a solid circular disc |04 having the sealing surface |03 on .one side and the tapering surface |05 on the other. The disc |04 is provided with an axial opening L06 adapted to receive a stationary rod |01 and a ycompression spring |08 encircles the rod. A floating collar |09 is secured on the inner end of the rod |01 by means of the nut |10, `and this collar is adapted to slide in axial keywa-ys Closure l2 is threaded into one end of the opening |05 and act-s to maintain ythe parts in assembled relationship. A cover ||.3 lmay ibe brazed into the counter-bore I i 4 to enclose the nut H0. Construction of the val-ve assembly is with a ,horizontal trip tube |23 and |24which are xed thereto and extend in directions parallel to the piston vrods |1 and |,8 in telescopic relation with respect to the stationary guide rods |23a and |2411 respectively. Each of these tubes |23 4and |24 is secured to its respective piston -by means of ,screw fittings |32 and extends through an aperture |33 provided in the vertical plate |20. Trip fingers |25 and |26 are ad.- justably mounted on each ofthese tubes and are adapted to contact spa-ced electric switches |21 and |28 ofthe Mercoid type, and also to engage valve-operating plungers '|29 and |30. The electric switches |21 and |28 are adapted to energize the signal lamps |46 and |41 respectively.

The general scheme of operation requires that the feed pistons |9 and 20 advance sequentially within their respective cylinders 2| and 22. A

filler opening 24 when the feed piston '20 is in its retracted position as shown in Figure 3. Hy-

draulic fluid v,from the pump |4 is delivered under pressure Ato the rear end of the pressure cylinder I6, thereby causing the feed piston 2|) to mo-re forwardly in the 'cylinder 22. The ball of dough is trapped ahead of the piston 20 and is confined under pressure within the forward end of the feed cylinder 22.

A vent valve assembly generally designated |45 is provided near the forward end of each of the feed cylinders in order to permit entrapped air to .escape so that the entire mass of material ahead of the feedpiston may comprise dough material to be extruded. As shown in Figure 9, the spring |45a. acts to move the valve member |49 away from its Yseat |49. As the f eed piston 20 continues its forward movement within the cylinder 22 the entrapped air is `bled olf through the vent valve |45 and the ball of dough takes the shape of the forward end of the cylinder and fills al1 of the space therein, the

acteert |51 untilthe feed piston 20 encounters resistance againstthe ballof dough in the feed cylinder 22. Upon encountering-such resistance the pressure required to vcontinue moving` the-piston' |80 increases. At this time the check valve |59 closes sure uid passes by wayy of manual control valve |78 and hydraulic line |8| to the small diameter end of: thefour-way controlV valve |63. The central spool |65 is shifte'dfrom' the position shown in Figure 12 to the position shown in Figure 13, l soithat. the pressure'uid to the outlet Si; is shut off and instead pressure fluid is delivered into the outlet |82 which communicates with the forward end of' the cylinder l5. The piston |70 then begins its retracting movement toward the vrear end of the cylinder under rapid traverse. The piston |70 reaches the rear end of the cylinder I and remainsv at rest while the forwardmotion of `the piston |80 continues at relatively slow speedy under high pressure.

When the adjustable nger |26 on the trip tube |24 engages the 'valve operating plunger |30 on the four-'way pilot valve |83, the. hydraulic line |85 is connected to the hydraulic line 9d` so that pressure fluid isfdeliveredrt'o they large` diameter end of the four-way valveassenribly |53, thereby shifting the' spool |65 back to the position shown Yin-A liigurev 12; The spool shifts to the left as shown in Figure 12 even though pressure exists in the small' diameter end because of the larger area of the large diameter end of this valve assembly. The piston |70 is then caused to move forwardly inv the cylinder l5 since the pressure fluid from the l-ine |6| passes through inlet |t2 and through outlet |64 into the hydraulic line |66. When the balll of dough ahead of the feed piston I9 builds up sufficient resistance, the pressure in the cylinder |,5 reaches a value above that for which the sequence valve |67 is set. Accordingly, the sequence valve |67 opens, admitting pressure flu-id through line |68, manual control valveV |69, and line |87Y into the small diameter end of the four-way control valve |72. This causes the piston |80 to retract within the cylinder I6. Y A l lhiscycle of operations continues so long as Aballs'o'f doug-h are supplied to the respective feed cylinders. The' trip fingers |25 and |26 are so positioned with respect-to their respective trip tubes l|23 and |26 thatthe actuation of ther-fourway pilot valves |98 and |83v occurs when the respective feed piston is Vvery nearv the end of its forward stroke.V

,Y The. machine is arranged-so that it may be operated from either' sida The various valves in 'the hydraulic system as shown diagrammatically {Figure 11 are mounted on parallel panels which are substantially duplicates'. As. shown in Figure 1' each' of these' panels may be arranged with the metering valve at one vend of the panel andthe four-way control valve at the other end.

The panel shown in Figure 1 includes the metering valve |53, the check valve |53, the manual control valve |78, the four-way pilot valve |93, the adjustable sequence valve |77, and the fourway control `valve 72.` The counterpart for each of these valves as shown ismounted on. the duplicate panel on the other side of the machine.

Fir-om the aboveldescription it will be understoodv that each four-way pilot valve initiates forvvari'Y movement of the feed piston on the votlieisid'er of the machine. Retracting movenlentrofteach of the feed pistons is initiated by lthe. pressure'relief valve on thev otherside of the 'machine f AS shown in Figure` 10`, the four-'way pilot valve |33 is `operatedv byla plunger |88 'carrying a cam .follower- |89.. The plunger` |88 is spring loaded.

to/hold the cam follower |89 against the underside of the cam |90 which is Xed on the stuloV Shaft |91. One end of the Stub Shaft ISE is i connected to a' universal joint |92 and its other endfis'connectedto 'a manual operating lever |93.` llA"hecuring sleeve |94 is'provided for the shaft |9l, and thisbe'aring. sleeve is Xed tothe lower end of the*y vertically'reciprocable plunger |30 which is. slidably mounted within a guide sleeve |95 carried on the frame. The roller |90 carried on the plunger |30 is adapted to be contacted by the linger' |26V which is adjustably mounted on the trip tube |24: When the tripnger |29 contacts the roller |95 it movesA the plunger |39 downwardly'within the guide sleeve |95 and moves the shaft |9| downwardly with it, thereby causing thev cam t'o depress the roller |99 and valveA plunger |88.

' The universal joint |92 is connected to a crosssh'aft |97A which* extends across the machine to thec'ontrol panel onv the other sidethereof where it connects'to a structure'identical to that shown inFigure 10 for-*operating the other four-way p-ilot'valve |98: The/manual control lever |93 on the shaft |9| may be actuated to rotate the cam |90 and thereby actuate the four-way pilot valve |83 when desired. This manual control lever |93 also acts Vthrough the cross-shaft |97 to actuate the four-'way pilotva-lve |98 on the other control panel; that' is, both' valves may be operated in unison from either side of the machine and the cams rare shaped. sol that when one pilot valve is opened the'other is closed.l The universal joints |92rat-opposite ends of the cross-shaft |97 permit the plungers |29 and |30 to move vertically independentlyv of each other. The principalusefulness for lthe manual control levers |93 is to providey a meansfor changing the normal cycle of operation of the feed pistons for tests, inspection, repair, etc;

The manual control valves |59 and |78 normally connect their respective pressure relief valvesfto the four-way control valve on the other side'of the machine. manual control valveshas the eect of supplying pressure fromthe hydraulic lines |99 and 290 to the four-way control valves on the other side of the machine', s'o that if it should be necessary to shift the position of the spools |65 Within the lfour-way control valves for any reason this may drain. These val-ves are of conventional type andthe drain connections are likewise conventional, although they are not specifically identified by numeralsl ljavingfully described my invention, it is to be understood that I do not wish'to be limited to the details herein set forth, but my invention is of the full-` scope i of the appended claims.

Actuation of either of these claim: n l c l. In an extrusion device, the combination of a casing member having a longitudinal opening; a stem member extending longitudinally through said opening and cooperating with the casing member to define an annular passageway, said members being mounted for relative longitudinal. movement; cooperating parts at Aone end of said members forming a ring orifice; said cooperating parts including stop shoulders axially engageable to limit the minimum width of the ring oriiice;

means at the other end of said members for effecting relative longitudinal movement between them, whereby the width of said orice maybe increased, said means vincluding a nut positioned outside the casing member and threadedly connected to the stem member, and key means for preventing relative turning lbetween said members; and inlet means in the casing member intermediate the ends thereof whereby a material to be extruded through the orice may be admitted into the annular passageway.

2. In an extrusion device, the combination of a casing having a vertical opening; a non-rotaryA vertical stem extending longitudinally through said opening and cooperating with the casing to define an annular passageway; an `annular element ixed on the casing closing one end of the opening, the stem being mounted for vertical movement relative to said annular element; cooperating parts at the lower end of the casing and stem forming an orifice; said cooperating parts including stop shoulders axially engageable to limit the minimum width of the ring orifice;

adjustment means at the upper end of said stem ment fixed on the casing closing one end of the opening, the stem being mounted for vertical movement relative to said annular element; cooperating parts at the lower end of the casing and stem forming a ring orifice extending horizontally therearound; adjustment means at the upper end of said stern for effecting vertical movement thereof, whereby the width of said ring orifice may be varied, said means including a thrust bearing on the annular element, a nut mounted on the thrust bearing and threadedly connected to the stem member, and key means on the annular element for preventing relative turning between said members; and inlet port means in the casing member intermediate the ends of the opening whereby a material to be extruded through the ring orifice may be admitted into the annular' passageway.

4. In an extrusion device, the combination of a casing having a longitudinal opening terminating in a downwardly extending rim; a stem extending longitudinally through said opening and cooperating with the casing to define an annular passageway, the stem being mounted for longitudinal movement in the passageway and having 12 a ring orice; keymeans for preventing relative rotation between the stem and the casing; means on said stem remote from said orifice for effecting relative longitudinal movement of the `stem whereby the width of said orifice may be varied; and stop means on the cap for limitingmovement of the stem in one direction, the stop means including a plurality of circumferentially spaced projections adapted to engage the lower end of the rim, the cap having slots defined between adjacent projections through which material may be extruded while'the projections are in contact with the rim. n Y

5. In an extrusion device, the combination of a casing having a longitudinalV opening terminating in a downwardly extending rim; a stem extending longitudinally through said opening and cooperating with the casing to define an annular passageway, the stem being mounted for longitudinal movementin the passageway and having a cap thereon cooperating with the rim to form a ring orifice; means on said stem remote from said orifice for veffecting relative longitudinal movement of the stem whereby the width of said orifice may be varied; key means forpreventingrelative rotation between the stem `and the casing; and a series of radialiins on the cap slidably mounted within the rim and adapted to separate the material extruded through the ring orifice into a plurality of strips.

6. In a device of the class described having an extrusion head provided with a passageway, the combination of: a first feed cylinder assembly operatively connected to said passageway; a second feed cylinder assembly operatively connected to said passageway, each of said cylinder assemblies having a check valve associated therewith and operatively interposed between each assembly and said passageway. each check valve acting to permit flow from its respective feed cylinder assembly toward the extrusion orifice but acting automatically to prevent return iiow, each of said cylinder assemblies including a piston reciprocable within a cylinder; power means for sequentially actuating said pistons; and control means associated with said power means adapted to maintain pressure on one feed piston at the end of its operative stroke until that pressure is substantially equalled by the pressure on the other piston whereby the pressure in said passageway is maintained substantially constant.

'7. In a device of the class described having an extrusion' head provided with a passageway, the

' combination of: a plurality of reciprocating feed a cap thereon cooperating with the rim to form means each operatively connected to deliver material into said passageway, each of said means having a check valve associated therewithautomatically acting to prevent return movement of material into the feed means; power means lfor sequentially actuating said feed means; andtiming means associated with said' power means adapted to maintain pressure on one feed means at the end of its operative stroke until that pressure is substantially equalled by the pressure on another feed means, whereby the pressure in said passageway is maintained substantially constant throughout the operating cycle of the feed means.

8. In a device of the class described having an extrusion head provided with a passageway, the combination of: a first piston and cylinder assembly operatively connected to said passageway; a second piston land cylinder assembly operatively connected to said passageway, each of said cylinder assemblies having a spring urged check valve associated therewith and operatively interi3 posed between each cylinderv assemblyiand said passageway, eachv check valve acting" toAJ permit iow from its respective cylinder assembly' toward said passageway but acting automatically to pre'- vent return flow, each of said cylinder assemblies including a power piston reciprocable within' a cylinder; means for supplying fluid under pressure for sequentially actuating sa-i'd' pistons, said means being adapted tomaintairrpressureon one power piston at' the` end of its operativestroke until that pressure is substantially equalled by the pressure on the other power piston whereby the pressure in said passageway is maintained substantially constant. Y Y

9. In an extrusion device having an extrusion head provided with av passageway leading toA a ring orifice, the combination of `a' cutter encircling the ring orifice and mounted for' reciprocation relative tothe extrusion head; means providing a oating mountingV for said cutter be'- tween opposed compression springs, said mount'- ing normally maintaining the Vcutter on one side of the orifice; means independent of the springs for adjusting the normal position of theo-utter; and positive means for moving the cutter' including' a rotary cam adapted to move'the' cutter'in'a direction to compress' one of the' springs, the cutter being moved in the other' direction across the oi'iiice by the' energy in the compressed spring.

lo; In an extrusion device havingan extrusion head provided with a passageway' leading' to an extrusion oriiice, the combination of a plurality ciprocable feed elements each operatively connected to said passageway;' means forre'ciproeating said feed elements oomprisinga piston and cylinder assembly associated with each, said assemblies each including' a' power piston recipro'c'able' within a power cylinder; me'ans'for'alter'- nately introducing pressure iiui'd into opposed ends of said power cylinders' for reciprocating the power pistons in sequence, said rne'ajns` including *Y a control valve associated with each power cylinder, each control valve having pressure' responsive'means operatively connected-to actuat'e' it; and hydraulic connections forv transmitting' ui'd pressure from each power cylinder to' one' of said pressure responsive means whereby each control valve may be actuated by increase' in' pressure in another power cylinder.

1'1. In an extrusion device having aneatrsi'on head provided with a passageway leading to an extrusion orice, the' combination of a pairv of iecipro'cable feed' elements each operatively oonn'ected'to said passageway; a 'ch'ecl'r valve interposed between each feed element and4 said passageway; means for reciprocating said feed elements comprising a piston and cylinder assembly associated with each, said assemblies each including a power' piston reciprocable within a power cylinder; means for alternately introducing pressure iiuid into opposed ends of said power .cylinders for reciprocating the power pistons in sequence, said means including a control" valve associated with each power cylinder, eachcontrol valve having pressure responsive means operatively connectedto actuate it; and hydraulic connections for transmitting fluid pressure from each power cylinder to one of said pressure. responsive means whereby each control Valve may be actuated by increase in pressure in the other power cylinder.

12. In an extrusion device having an extrusion head provided with a passageway leading to an extrusion orifice, the combination of a pair of reoiprocable feedeelementseach operatively oonnecte'dtbsaid passageway; means'for' reciprocatfluid under pressure to' said control valves; trip means'as'sociated with eachA power piston adapted to be* actuated upon predetermined travel of the piston; hydraulic' means operatively connecting each' Vtrip' means with the control valve for the other' piston, whe'reby'forward movement of each piston is` initiated'l by' predetermined travel of the other piston; a pressure responsive sequence valve'for each or" the'power" cylinders each opera'ti'v'ely' connected to the' 'rearward end of one of said cylinders; and hydraulic connections wl'iereb'yl each sequencevalve may actuate the control valve furthe other piston to initiate retracti'ng' movement of the' other' piston when the pressure in the rearward end' of its respective cylinder' exceeds a predetermined value'.

132.111 an extrusion device, a' pair of power cylinder's each having a power' piston reciprocable therein, a separate control valve for each of said power cylinders', hydraulic conduits' connecting each' control valve-'tc the opposed eri-ds of' the eyl-` means operatively connectingeach trip means with the control valve' for' the other piston', wherebyforwar'd movement of each piston is initiated by predetermined travel of the other'pis'- ton; a pressure responsive sequence valve for each' ofthe' power cylinders each operatively connected. tothe rearward end ofoiie of said cylinders; and hydraulic connections whereby each sequence valve may act'uate the control valve for the other piston to initiate retracting movement of the other pistonwhenthe' pressure in the rearward end'of`its respective cylinder exceeds a predeterminedv value.

y 1'4'. In an extrusion device having an extrusion head provided with a passageway leading to an extrusion orifice, thecombination of a pair of reciprocating feed elementsV operatively connected to said passageway; a check valve interposed between each of' the feedl elements and said passageway, each of the check valves including a relatively stationary stem and a head movable on the stemland adapted to engage a seat, the head having a central( opening; a compression spring enclosed within said opening, andconned within the head, the spring normally acting to move the head in a direction to engage the seat.

15. In an extrusion device having an extrusion head provided with a passageway leading to a ring orilice, the combination ofV a cutter encircling the ring. oriiice, means provldfing a iioating mounting for said cutter between opposed cornpression springs, saidL mounting normally mainlIl'iI-g il'l Clttef" Oi i Si'de' f tile loe, eaiis d'ep'edt of the springs' foi' adjusting the nonnalv position of the cutter at 'rest with respectfto the orifice, and power meansindependent ofthe springs for positively moving the cutter in one direction to compress one of the springs, the cutter' vbeing moved in the other direction CUS h 'I'flo by the lgy .in the CbmDlS'Sd spring.y Y

161 Irrl an extrusion device having an' extrusion head provided' W'th a passageway' leading l'tc-'an Y la@faz-,fare

1d extrusion' orifice, the combination of a plurality of reciprocable feed element-s each operatively connected to said passageway, means for reciprocating said feed elements comprising a piston and cylinder assembly associated with each of said feed elements, said assemblies each including a power piston reciprocable within a power cylinder, means for alternately introducing pressure fluid into opposed ends of said power cylinders for reciprocating the power pistons in sequence, said last named means including a control valve associated with each power cylinder, a pressure responsive sequence valve for each of the power cylinders, and conduit means operatively connecting each sequence valve to the rearward end of one of said cylinders and to each lof said control valves, each sequence valve acting upon increase in pressure in the rearward end of its respective cylinder above a predetermined value to cause the control valve for another cylinder to initiate retracting movement of the power piston therein.

17. In an extrusion device having an extrusion head provided with a passageway leading to an extrusion oriiice, the combination of a pair of reciprocable feed elements each, operatively connected to said passageway, a check valve interposed between each feed element and said passageway, means for reciprocating said feed elements comprising a piston and cylinder assembly associated with each of said feed elements, said assemblies each including a power piston reciprocable within a power cylinder, means for alternately introducing pressure fluid into opposed ends of said power cylinders for reciprocating the power pistons in sequence, said last named means including a control valve associated with each power cylinder, a pressure responsive sequence valve for each of the power cylinders, and conduit means operatively connecting each sequence valve to the rearward end of one of said cylinders and to each of said con,- trol valves, each sequence valve acting upon increase in pressure in the rearward end of its respective cylinder above a predetermined value to cause the control valve for the other cylinder to initiate retracting movement of the power piston therein.

18. In an extrusion device, the combination of an extrusion head having a passageway leading to an extrusion orice,` a feed cylinder assembly operatively connected to said passageway, a check valve positioned between the feed cylinder assembly and passageway acting auto- `matically to permit new from the assembly to the passageway but to prevent return flow, the feed cylinder assembly including a piston reciprocable within a cylinder, and a vent valve assembly associated with the cylinder positioned near the check valve, the vent valve assembly including a movable element opening inwardly of the cylinder, a spring biasing the valve element toward open position so that air trapped vwithin the cylinder during forward motion of the piston may escape from the cylinder, the vent valve being closed by mechanical contact with the material being extruded during forward motion of the piston.

19. In an extrustion device, the combination of an extrusion head having a passageway leading to an extrusion orifice, a feed cylinder assembly operatively connected to said passageway, a check valve positioned between the feed cylinder assembly and passageway acting automatically to permit flow from the assembly to the passageway but to prevent return iiow, the

feed cylinder assembly including a piston reciprocable within a cylinder, and a vent valve assembly mounted on the piston and including a movable valve element opening in the direction of forward movement of the piston, a spring lbiasing the valve element toward open position so that atmospheric air may enter the cylinder during retracting movement of the piston, the movable'valveV element being closed by direct contact with material to be extruded during forward motion of the piston.

20. In an extrusion device, the combination of z a casing having a vertical opening, a nonrotary vertical stem extending longitudinally through said opening and cooperating with the casing to kdeiine an annular passageway, guide means at the upper end of the casing for guiding the stem for vertical movement thereon, said guide means including a sealing element slidably engaging the stem, cooperating parts at the lower end of the casing and stem forming a ringV orifice extending horizontally therearound, adjustment means at the upper end of said stem for eiecting vertical movement thereof, whereby the width of said ring oriiice may be varied, said adjustment means including a thrust bearing supported on the casing, the stem having external threads on the upper end thereof, a nut mounted on the thrust bearing and having internal threads engaging said stem threads, and means for preventing relative turning movement between said stem and casing, said means Alast named including an axial keyway formed and la key fixed relative to the casing extending into said keyway.

21. In an extrusion device having an extrusion head provided with a passageway leading to a ring orifice, the combination of a cutter encircling the ring orifice, parallel rods positioned on diametrically opposite sides of the cutter, means securing the rods to the cutter, a guide bushing encircling a portion of each rod, means adjustably mounting each guide bushing relative to the extrusion head, the rods being axially slidable in said guide bushings, springs resisting axial movement of the rods in one direction, and power means for moving therods and cutter in said direction to compress the springs, the rods and cutter being moved in the other direction by the energy in the compressed springs.

LEONDAS C. MILLER.

References Cited in the file of this patent 

